DUMP(8)DUMP(8)NAMEdump - incremental file system dumpSYNOPSIS
/usr/etc/dump [ key [ argument ... ] filesystem ]
DESCRIPTION
Dump copies to optical disk or magnetic tape all files changed after a
certain date in the filesystem. The key specifies the date and other
options about the dump. Key consists of characters from the set
0123456789fusdoOWn.
0-9 This number is the `dump level'. All files modified since the
last date stored in the file /etc/dumpdates for the same
filesystem at lesser levels will be dumped. If no date is
determined by the level, the beginning of time is assumed; thus
the option 0 causes the entire filesystem to be dumped.
f Place the dump on the next argument file instead of the tape or
optical disk. If the name of the file is ``-'', dump writes to
standard output.
u If the dump completes successfully, write the date of the
beginning of the dump on file /etc/dumpdates. This file records a
separate date for each filesystem and each dump level. The format
of /etc/dumpdates is readable by people, consisting of one free
format record per line: filesystem name, increment level and
ctime(3) format dump date. /etc/dumpdates may be edited to change
any of the fields, if necessary.
s The size of the dump tape is specified in feet. The number of
feet is taken from the next argument. When the specified size is
reached, dump will wait for reels to be changed. The default tape
size is 2300 feet.
d The density of the tape, expressed in BPI, is taken from the next
argument. This is used in calculating the amount of tape used per
reel. The default is 1600.
W Dump tells the operator what file systems need to be dumped. This
information is gleaned from the files /etc/dumpdates and
/etc/fstab. The W option causes dump to print out, for each file
system in /etc/dumpdates the most recent dump date and level, and
highlights those file systems that should be dumped. If the W
option is set, all other options are ignored, and dump exits
immediately.
w Is like W, but prints only those filesystems which need to be
dumped.
n Whenever dump requires operator attention, notify by means similar
to a wall(1) all of the operators in the group “operator”.
o Specifies that the device to dump to is a removable disk. The
NeXT OMD-1 Optical Disk is the default drive when this flag is
specified.
O When dumping to an optical or floppy disk, the size of the disk,
expressed in megabytes (1048576 bytes), is taken from the next
argument, so it's after any more characters in the key. For
example, the size of a NeXT OMD-1 Optical Disk is 237 megabytes.
You can, and sometimes must, specify a non-integral size; an
extended density floppy disk is 2.6 megabytes. See /etc/disktab
for information on disk geometry.
If no arguments are given, the key is assumed to be 9u and a default
file system is dumped to the default tape.
Dump requires operator intervention on these conditions: end of
removable disk or tape, end of dump, removable disk or tape write
error, removable disk or tape open error or disk read error (if there
are more than a threshold of 32). In addition to alerting all
operators implied by the n key, dump interacts with the operator on
dump's control terminal at times when dump can no longer proceed, or if
something is grossly wrong. All questions dump poses must be answered
by typing “yes” or “no”, as appropriate.
Since making a dump involves a lot of time and effort for full dumps,
dump checkpoints itself at the start of each tape or removable disk
volume. If writing the tape volume fails for some reason, dump will,
with operator permission, restart itself from the checkpoint after the
old tape has been rewound and removed, and a new tape has been mounted.
If writing the removable disk fails for some reason, dump will prompt
the operator to restart from the checkpoint after the old removable
disk has been ejected and the new removable disk has been inserted.
Dump tells the operator what is going on at periodic intervals,
including usually low estimates of the number of blocks to write, the
number of removable disks or tapes it will take, the time to
completion, and the time to the disk or tape change. The output is
verbose, so that others know that the terminal controlling dump is
busy, and will be for some time.
Dump looks in /etc/swaptab for swapfiles that reside on the filesystem
being dumped. If any matches are found, those files are not included
in the dump.
Now a short suggestion on how to perform dumps. Start with a full
level 0 dump
dump 0un
Next, dumps of active file systems are taken on a daily basis, using a
modified Tower of Hanoi algorithm, with this sequence of dump levels:
3 2 5 4 7 6 9 8 9 9 ...
For the daily dumps, a set of 10 tapes per dumped file system is used
on a cyclical basis. Each week, a level 1 dump is taken, and the daily
Hanoi sequence repeats with 3. For weekly dumps, a set of 5 OD's or
tapes per dumped file system is used, also on a cyclical basis. Each
month, a level 0 dump is taken on a set of fresh OD's or tapes that is
saved forever.
DUMPING TO REMOVABLE DISK
On systems where Workspace Manager is running, the operator should wait
intil the Insert Disk panel appears before inserting a disk.
Otherwise, autodiskmount(1) will try to mount the disk on behalf of the
Workspace Manager.
For example, to perform a level X dump to the internal floppy disk, use
a command of the following form:
dump XOf 2.6 /dev/rfd0a
DUMPING TO EXABYTE TAPE
When used with the Exabyte tape drive, one 120-minute 8mm tape will
hold 2.131 billion bytes (or 1.985 GB, where "giga" is 1024^3). This
is the equivalent of 1,332,183 feet of 1600bpi reel-to-reel tape. So,
a dump which wanted to use "almost all" of the Exabyte tape would
specify:
dump Xfs... /dev/nrxt0 1200000 ...
(or similarly with /dev/rxt0).
FILES
/dev/rsd0a default filesystem to dump from
/dev/rxt0 default tape unit to dump to
/dev/rod? default optical disk
/dev/rfd0a internal floppy disk
/etc/dumpdates new format dump date record
/etc/fstab dump table: file systems and frequency
/etc/group to find group operator
SEE ALSOautodiskmount(1), restore(8), dump(5), fstab(5)DIAGNOSTICS
Many, and verbose.
Dump exits with zero status on success. Startup errors are indicated
with an exit code of 1; abnormal termination is indicated with an exit
code of 3.
BUGS
Dumps made with dump can't be restored by other vendors' restore
programs. In order to make dumps that can, use dump.old.
It is hard to measure an optical disk in terms of tenths of inchs and
size of inter-record gap. A multi-machine, multi-media solution should
be sought.
Dump should have some file that it consults that contain inode numbers,
names of files and directories, and names of users and/or groups to not
dump to removable disk/tape. This feature would come in especially
handy to avoid dumping /usr/man/cat, /NextLibrary, and /NextApps.
System administrators can get around this by writing a program that
changes the modification time for these files.
Because of the interworkings of rmt and rdump, it is only possible to
run rdump from one NeXT machine to another. This is in part due to the
fact that the ioctls for the removable disk differ from the mag tape
ioctls available with rmt, and in part due to the fact that NFS does
not implement remote device ioctls.
Fewer than 32 read errors on the filesystem are ignored. Each
removable disk or reel requires a new process, so parent processes for
reels already written just hang around until the entire tape is
written.
Dump with the W or w options does not report filesystems that have
never been recorded in /etc/dumpdates, even if listed in /etc/fstab.
It would be nice if dump knew about the dump sequence, kept track of
the tapes scribbled on, told the operator which tape to mount when, and
provided more assistance for the operator running restore.
4th Berkeley Distribution August 22, 1989 DUMP(8)